I'm not sure what you mean with turntable and trackball mode? Has that something to do is camera navigation possibly?

Sorry, the wording in my question was too vague. Also, I don't know why, after all this time, I noticed this behavior last night. It's not a big deal either, just a curious point, not even a request

What I meant is that the rotation in blender (on perspective mode) can function in two ways. In one mode (Trackball) it is identical to C3D's mode, where the view can rotate along the viewer's Y (vertical) and X (horizontal) planes. In Turntable mode, you can rotate in the Z plane as well (depth), and you can sort of look at things sideways. It's hard to explain, you have to try it if you really wanna know what I mean